Method of making an electron gun for a cathode ray tube and jig assembly therefor



Apnl 21, 1970 H. H. AIKEN 3,507,020

METHOD OF MAKING AN ELECTRON GUN FOR A CATHODE RAY TUBE AND JIG ASSEMBLY THEREFOR Filed Dec. 6, 1967 T 4 Sheets-Sheet 1 ASSEMBLE T0 65 ON JIG BASE (see H62) JIG BASE with ELECTRODES CLAMP ASSEMBLED ELECTRODES (see HG 6) m ADJUSTED Posmou 0N JIG BASE JIG BASE 8T CLAMP with CLAMPED ELECTRODES l APPLY GLASS BEADs To CLAMPED (see mg) ELECTRODES ON JIG BASE JIG BASE B CLAMP with BEADED ELECTRODES c.LAMP

PLACING CLASS A BEMovE CLAMP FROM BEADED STEM IN (see F|G.9)

STEM HOLDER ELECTRODES 8| JIG BASE JIG BASE with BEADED STEM HOLDER ELECTRODES (GUN BODYT JIG BAsEBsTEM HOLDER MM GUN BODY asTEM STEM ATTACH STEM HOLDER to JIG BASE] (see FIG. ll)

wELD STEM HOLDER CONDUCTORS To ELECTRODES sTEM JIG BASE a STEM HOLDER HQLDER with COMPLETED GUN REMOVE STEM BDLDEBB 5 MG COMPLETED GUN from JIG BAsE FIG 9 COMPLETED GUN A A 3 l I 40 April 21, 1970 H. H. AIKEN 3,507,020

METHOD OF MAKING AN ELECTRON .GUN FOR A CATHODE RAY TUBE AND JIG ASSEMBLY THEREFOR Filed Dec. 6, 1967 4 Sheets-Sheet 2 HOWARD H. AIKEN ALLAN I. PARVIN SEYMOUR JANOWSKY CHARLES M. TAITEL HAROLD .SKURNIK av W I monusvs Aprll 21, 1970 H. H. AIKEN METHOD OF MAKING AN ELECTRON GUN FOR A CATHODE RAY TUBE AND JIG ASSEMBLY THEREFOR 4 Sheets-Sheet 5 Flled Dec. 6, 1967 INVENTORS HOWARD H. AIKEN ALLAN l PARVIN SEYMOUR JANOWSKY CHARLES M. TAITEL HAROLD SKURNIK BY SW, IM,M MR. ATTORNEYS H. H. AIKEN April 21, 1970 3,507,020 METHOD OF MAKING AN ELECTRON GUN FOR A CATHODE RAY TUBE AND 'JIG ASSEMBLY "THEREFOR 4 Sheets-Sheet 4 Filed Dec. 6, 1967 FIG. l0

FIG. A

INVENTORS HOWARD H. AIKEN ALLAN PARVIN SEYMOUR JANOWSKY CHARLES M. TAITEL HAROLD SKURNIK SL LA, W, M,

miymm uk ATTORNEYS United States Patent US. Cl. 29-25.16 Claims ABSTRACT OF THE DISCLOSURE An electron gun for a cathode ray tube is completely manufactured by a novel assembly line process on a unique jig assembly. The process includes assembling all electrodes on a transportable jig base by referencing central apertures of the electrodes on the jig, clamping the assembled electrodes on the jig and sending the jig through a beading operation. This is followed by removing the clamp and applying a steam holder with a glass stem to the jig prior to welding of the stem conductors to the electrodes. The jig assembly includes a jig base with a stepped cylindrical pin for the electrodes, a clamp which is removably attachable to the jig base, and a stern holder which is likewise removably attachable to the jig base and in cludes appropriate stops for aligning the glass stem with the electron gun body on the jig base.

BACKGROUND OF INVENTION Field of invention This invention relates to a method of making an electron gun for a cathode ray tube and a jig assembly utilized in this method.

PRIOR ART Electron guns for cathode ray tubes are manufactured in great quantity, primarily for use in home television receiver sets. These electron guns, particularly for black and white TV tubes, have been more or less standardized utilizing a basic construction of a number of spaced electrodes having central apertures therein which must be aligned. The electrodes have lugs on their outer periphery which are held in glass beads. These beads provide rigidity to the electron gun body and hold the electrodes in spaced relation. A glass stern having electrical conductors extending through flanges therein is positioned in spaced relation to the gun body and these conductors are attached to appropriate ones of the electrodes by welding or the like.

It has been known in the prior art to provide a jig for positioning the electrodes of an electrode gun for assembly operations. However, the prior art jigs did not provide for retention of the electrodes of the gun on a single central mandrel or post with spacers included with the jig for all assembly operations. Another disadvantage of the prior art was in adapting of the jig to an assembly line process for the complete making of the gun including application of the stem as well as beading.

SUMMARY OF INVENTION With the jig assembly of this invention, the electrodes can be assembled and the jig passed through a beading operation and the electron gun body carried on the jig while a glass stem is applied. In other words, in an assembly line with an automated operation the jig itself goes through all of the steps of the process.

3,507,020 Patented Apr. 21, 1970 In this invention electrodes are aligned on a transportable jig by referencing of central apertures in the electrodes on the jig and the aligned electrodes are then clamped and fed through a beading machine, after which the clamp is removed and a stem holder attached to the transportable jig to hold a glass stem in aligned position with the electron gun body for further assembly operations. The jig assembly includes a jig base with an aligning pin. A clamp is removably attachable to the jig base to clamp the electrodes in position for attaching of glass beads, and a stem holder is also removably attachable to the jig base for later operations of attaching conductors in a glass stem to appropriate electrodes. Movable spacers are carried by the jig base for positioning between gun electrodes.

BRIEF DESCRIPTION OF DRAWINGS The invention will be described with respect to a preferred embodiment illustrated in the accompanying drawings in which:

FIG. 1 is a block diagram showing the steps of the method of assembly of the electron gun of this invention;

FIG. 2 is an exploded perspective view of the jig base and electrodes to be assembled thereon;

FIG. 3 is a sectional elevation view of the jig base taken along line 33 of FIG. 2;

' FIG. 4 is a sectional elevation view of the jig base taken along line 4-4 of FIG. 2;

FIG. 5 is a perspective view of a clamp removably attachable to the jig base;

FIG. 6 is a longitudinal sectional elevation view of the clamp;

FIG. 7 is a transverse sectional elevation view of the clamp taken along line 77 of FIG. 6;

FIG. 8 is a side elevation View of the clamp and jig base in a horizontal position for passing through a beading operation;

FIG. 9 is a perspective view of the jig base with the beaded electrode assembly, termed electron gun body, thereon;

FIG. 10 is a perspective view of a stem holder removably attachable to the jig base;

FIG. 11 is a side elevation view of the stem holder of FIG. 10 attached to the jig base and having a glass stem therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates the general steps of the process and movement of the gun and jig components during manufacture of the electron gun.

The first step illustrated in FIG. 1 is assembling gun electrodes G through G on a transportable jig base 12, see FIG. 2. As shown in FIG. 2, the jig base 12 has assembled thereon first G G and G which have already been formed into a subassembly as shown, then a spacer S followed by G followed by another spacer S and then G Lugs L of all electrodes are vertically aligned.

The jig base 12 includes a base plate 14 having a pair of legs 16 and 18. Leg 16 mounts a pin 20 for receiving spacer S when not in spacing use and leg 18 carries a spring clamp 22 for holding spacer S when not being used to space G and G An upstanding jig body 24 is secured to the base by suitable screws 25 and includes a transverse bore 26 therethrough for receiving a locking pin of a clamp or stem holder. Extending transverse to bore 26 is a locking plunger 28 having a split ring 30 on one end thereof, an undercut diameter 32 adjacent the center portion thereof, and a head 34 on the other end. A spring 36 biases the locking plunger outwardly as shown in FIG. 3 so that the full diameter portion of the plunger intersects the bore 26 for locking a pin extending through the bore.

In the body 24 there is a transverse slot 38 for accommodating an actuator 40 of a central movable alignment pin 44. A set screw 42 holds the end of pin 44 in actuator 40. Pin 44 extends upwardly and axially of the body 24.

A stepped alignment pin 46 provides, with its outer diameters, referencing alignment for the electrodes. The alignment pin 46 has one end held within an axial bore 48 in the body and is rigidly secured by a set screw 50.

The pin 46 includes steps 52, 54, 56 and 58. The electrode G is positioned over steps 52 and 54 and the diameter of portion 56 aligns both G and G as well as spacer S The small aperture in electrodes G and G are aligned on the extendable central pin 44. The jig base also has an aligning recess or blind bore 59 for the purposes of aligning a clamp or stem holder to be placed thereon.

In the first step of the process as illustrated in FIG. 1 the electrodes G G and G are first placed on the step pin 46, then spacer S is placed on pin 46, then electrode G is placed on the top of pin 46 and goes around the smaller diameter pin 44, which is extended as shown in FIG. 3. Then spacer S is placed on top of G and G is placed on top of S the small aperture in G also being aligned by the pin 44. The electrodes are then all rotatably aligned so that the lugs L on each electrode are positioned in alignment vertically beneath one another. These lugs L will receive the glass beads. The assembly thus has the electrodes all assembled spaced and aligned, although they are resting loosely on the top of the jig base as the jig base is sitting vertically upright.

The next step in the process is to clamp the assembled and positioned electrodes in their adjusted position. This is accomplished by applying a clamp 60, see FIGS. 5 and 6, to the side of the jig base and activating a clamping assembly 66 to clamp the assembled electrodes in their adjusted position.

As shown in FIGS. 5 and 6, the clamp 60 includes a base plate 62 mounting an elongated body 64 by suitable screws 65. A clamp assembly 66 is mounted on one end of the body 64 and a locking pin 68 with a recessed central portion 69 extends from the other end of elongated body 64. An aligning pin 70 extends outwardly from body 64 for mating with aligning recess 59 in the jig base. The clamp 60 is locked onto the jig base 12 while the jig base is in a vertically upright position, see FIG. 6, by means of locking pin 68 extending into bore 26 with pin 34 in the jig base pressed inwardly against the bias of spring 36 so that recess 32 does not obstruct insertion of pin 68. Then head 34 is released and spring 36 causes the pin 28 to move to the left as shown in FIG. 3 and lock recess groove 69 in locking pin 68. The dimensions of the clamp body are chosen such that when it abuts against the jig base in assembled condition in FIG. 6, the clamp assembly 66 is aligned with the assembled electrodes.

The base 64 of the clamp also has a pair of cradle ends 72 and 74 sandwiching a cradle bod 76 for cradling the G electrode and positioning it relative to the other assembled electrodes. A pair of side plates 78 and 79 are secured by screws 77 to the sides of the body 64. The tops of these side plates are used to position and support glass beads which are applied to the lugs L of the electrodes during a beading operation.

The clamp assembly 66 includes a flat clamp head 80 with a central recess 81 to accommodate pin 44. The head 80 is mounted on a plunger 82 biased downwardly by a spring 84 positionedbetween the head and an extension 86 from the body 64. The extension 86 has a bore 88 to accommodate sliding movement of the plunger 82 and a counterbore 90 to accommodate a bearing member 92 secured therein by a set screw 94. A bracket 96 mounts a handle 98 secured to a lever 99 to furnish toggle clamping action. With the handle 98 in the position of FIG. 6,

4 the clamp head bears on the inside of electrode G clamping all the assembled electrodes. In the position of FIG. 5 the clamp is released.

After the clamp is applied to the assembled electrodes as shown in FIG. 6, the jig base 12 and clamp 60- are turned on their side so that the electron gun is horizontal, see FIG. 8. The width of clamp base 62 is the same as the width of jig base 14 so that the jig and clamp can operate on the same assembly line track, whether the jig base is upright as in the initial assembly steps shown in FIG. 2 or horizontal as shown in FIG. 8.

The next step in the process is to apply glass beads to the lugs of the assembled electrodes while they are clamped on the jig base by sending the jig and clamp assembly shown in FIG. 8 in horizontal position through a suitable beading operation, in which glass beads B are softened and applied to lugs L to rigidity the electrode assembly and provide an electron gun body. v

After the beading operation the clamp 60 is removed by pushing in on plunger head 34 and the jig base 12 is again turned upright. At this time the jig base will have the electron gun body thereon as shown in FIG. 9. The pin 44 is retracted by pulling down on actuator 40.

While on the upright jig base 12, the electron gun body is sent through several other conventional operations such as inspection and testing and applying a cathode heater, etc. However, to make a complete electron gun from the electron gun body, a glass stem must be applied and conductors extending through the flange of the stern must be secured to certain of the electrodes.

A glass stem S, shown in FIG. 11, includes a flange S; having a number of conductors S extending therethrough. These conductors are attached to appropriate ones of the electrodes, as is known in the art. The stem must be positioned in a precise spacial relationship with regard to the electron gun body and aligned with the body. This position is maintained by welding certain of the conductors S to lugs of G The glass stem S is placed in a stern holder 100, see FIGS. 10 and 11. The stem holder 100 includes a base 102 and an elongated body 104. Extending from one end of the body is a locking pin 106 similar to locking pin 68 on the clamp and an alignment pin 108 similar to pin 70 on the clamp. A pair of stops 110 and 111 are secured by screws 112 to the body 104 and these stops reference the stern holder 100 to the sides of the glass beads B of the electron gun body.

An extension 114 on base 104 has curved cradle portions 116 and 118 for cradling the glass stern S. A toggle clamping arrangement 120 is provided for clamping the stem S between the two cradle portions. The clamp 120 includes a resilient clamping member 122 attached to an adjustable screw 124 having a nut 126 and secured to the end of a lever 128. A clamp actuating handle 130 is connected to the lever and to bracket 132 in a manner to provide a toggle clamp.

For positioning the flange Sf of the stem S relative to the electron gun body an adjustable stop is provided by the undersurface of the head 134 of an adjustable screw 136. This screw is threaded into extension 114 and is locked in adjusted position by a not 138.

In the final assembly operations the glass stem is placed in the stem holder and the stem holder is locked onto the jig base 12. Then the conductors S of the stem holder are welded to appropriate ones of the electrodes with two of the conductors being welded to two lugs of G by suitable welding equipment. The electron gun is then complete and may be removed from the jig base 12 after first releasing clamp 120 and removnig the stem holder 100.

As can be seen in from FIG. 1 the different components of the jig assembly such as the clamp 60, the stern holder 100, and the jig base 12 are reused and recycled from the end of their use in the assembly line operation to the point where they are introduced. The use of the jig base for carrying first the assembled electrodes, then the electron gun body and finally the completed electron gun throughout the entire process makes the assembly operations much simpler and greatly reduces the cost.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

We claim:

1. A method of making an electron gun for a cathode ray tube, the method comprising the steps of; assembling electrodes on a transportable jig base while aligning the electrodes by referencing central apertures therein on a portion of the jig base, clamping the assembly of electrodes onto the jig base with a clamp, applying glass beads to the sides of the asembled electrodes clamped on the jig base, then removing the clamp, placing a glass stem in a stern holder, attaching the stem holder to the jig base with the stem aligned and spaced from the beaded electrode assembly, welding conductors in the stem to appropriate electrodes of the beaded electrode assembly, and removing the completed electron gun from the jig base and stem holder.

2. A method as in claim 1 wherein the steps are carried out on an assembly line and the jig base passes completely through the assembly line.

3. A method as in claim 1 wherein the step of assembling electrodes utilizes spacers between at least some of the electrodes, the spacers being carried by the jig base.

4. A method as in claim 1 wherein the assembling of the electrodes includes assembling three electrodes on the jig base while referencing central apertures therein placing a spacer, another electrode, another spacer, and a further electrode on the jig base while aligning apertures of the electrode with central apertures of said three electrodes by referencing on the jig base.

5. A method as in claim 1 further comprising recycling the clamp after removal from the jig base by conveying the clamp around the beading station in a direction opposite to movement of the jig and assembled electrodes through the heading station.

References Cited UNITED STATES PATENTS 3,267,316 8/1966 Drake 2925.16 3,289,268 12/1966 Bernardis 2925.19 3,363,298 1/1968 Merchant et al. 2925.19 3,434,819 3/1969 Merchant et a1. 2925.16

JOHN F. CAMPBELL, Primary Examiner R. B. LAZARUS, Assistant Examiner 

